The answer:
according to Boyle's law concerning Pressure (P), Volume (V), Temperature (T) and number of mole (n) , we have the famous formula:
PiVi = Pf Vf,
Pi=1.9kPa
Vi= 4L
Vf = 12L
T=25
n=3
Pf = ?
let's find the value of Pf
from the equation
PiVi = Pf Vf we can have Pf= PiVi / Vf
Pf = 1.9*4 / 12 = 0.63
so the answer is <span>B. 0.63 kPa</span>
Answer : The activation energy for the reaction is, 119.7 J
Explanation :
According to the Arrhenius equation,

or,
![\log (\frac{K_2}{K_1})=\frac{Ea}{2.303\times R}[\frac{1}{T_1}-\frac{1}{T_2}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7BK_2%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%20R%7D%5B%5Cfrac%7B1%7D%7BT_1%7D-%5Cfrac%7B1%7D%7BT_2%7D%5D)
where,
= rate constant at 271 K
= rate constant at 281 K = 
= activation energy for the reaction = ?
R = gas constant = 8.314 J/mole.K
= initial temperature = 271 K
= final temperature = 281 K
Now put all the given values in this formula, we get:
![\log (\frac{2K_1}{K_1})=\frac{Ea}{2.303\times 8.314J/mole.K}[\frac{1}{271K}-\frac{1}{281K}]](https://tex.z-dn.net/?f=%5Clog%20%28%5Cfrac%7B2K_1%7D%7BK_1%7D%29%3D%5Cfrac%7BEa%7D%7B2.303%5Ctimes%208.314J%2Fmole.K%7D%5B%5Cfrac%7B1%7D%7B271K%7D-%5Cfrac%7B1%7D%7B281K%7D%5D)

Therefore, the activation energy for the reaction is, 119.7 J
A.)49.4974874 moles or 49.5 moles
B.)2.980808730172671e+25 or 3e+25
Answer:
igneous or metamorphic
Explanation:
Those two are sorta relvant
If it goes from a volume of x, then when the volume is doubled it will go to a volume of 2x. If you meant what happens to the pressure, then the pressure halves as volume doubles due to Boyle's law.